What is Kanmuriotoshi-zukuri in Japanese Katana terminology?

"Kanmuriotoshi-zukuri" (冠落造り) refers to a style of Japanese sword construction where the ridge side of the blade from the waist upwards is thinly shaved off, and the ridge line (Shinogi-suji) is extended to the tip (Kissaki). This style is often seen in short swords made by swordsmiths of the Yamato tradition from the Kamakura period to the Nanbokucho period.

This method of construction not only gives the sword a unique appearance but also enhances its functionality. By extending the ridge line to the tip, the sword's cutting ability is improved. The thinning of the ridge side also reduces the weight of the sword, making it easier to handle. This style is a testament to the skill and craftsmanship of the swordsmiths of the Yamato tradition, who were able to balance aesthetics and functionality in their creations."